1. Field of the Invention
A retractable piston syringe adapter for use in combination with a syringe in the removal of human tissue, fluid and/or cells for the diagnosis of pathological processes.
2. Prior Art
The pathological diagnostic technique of fine needle aspiration has become widely used.
An example of the technique which can be performed in a doctor's office, allows diagnosis of lesions, such as breast masses. In this technique a needle is inserted through the skin into the mass, organ, sack and a vacuum is applied to aspirate or withdraw cells or fluid from the target. The vacuum is created by withdrawing the syringe plunger. During the vacuum state, the user moves the needle up and down with one hand, causing cells, tissue and/or fluid to be cut free so that the vacuum will suck them into the barrel of the syringe. When an adequate sample is obtained, the vacuum is exhausted. The needle is withdrawn.
Needle aspiration usually involves a disposable syringe with an attached disposable needle. A syringe holder is presently used with the syringe, although the syringe may be used by hand without the holder. The syringe holder is a device made of a solid material such as metal, in which the disposable syringe and needle is inserted. The syringe holder allows the user to operate the syringe, including withdrawing its plunger with one hand,
U.S. Pat. No. 2,198,666 describes a syringe having a body and plunger to take up and expel fluid including a resilient spring that operatively engages the plunger to urge the plunger outwardly of ii the body and interlocking means operatively connected to the plunger and the body to position the plunger relative to the body in at least one intermediate position. The interlocking means comprises an engageable finger and recess means adapted to selectively accommodate the finger having a shoulder positively preventing outward movement of the plunger by the spring and provide a free passage in the opposite direction whereby the plunger may be freely actuated to expel the contents of the syringe against the spring tension only and a second passage disposed axially of the syringe open ended in both axial directions for permitting movement of the plunger completely out of the body.
U.S. Pat. No. 5,241,969 shows a syringe holder for the diagnostic technique of fine needle aspiration used in the diagnosis of cancer and other pathological processes. A stabilizing ring with or without a detachable extended stabilizing ring is placed on the skin around the mass which is to be needled. The needle is guided into the mass accurately as the syringe is held firmly by a syringe body holder which slides on guide bars. A vacuum is created by pulling the syringe plunger back with a plunger holder and cells and tissue from the mass are sucked into the syringe as the needle is moved in an up-and-down direction by the hand holding a handlebar. The depth of needle penetration is controlled by limit screws. When the sample is obtained, the vacuum is released. The needle is removed from skin and the sample is removed from the syringe.
U.S. Pat. No. 4,850,973 teaches an injection device adapted to fit various syringe sizes. The injection device is spring loaded and provides a firing barrel which in the cocked position is offset slightly from the central bore of the device. When the device is fired, the firing barrel is aligned with the central bore and projects the needle portion of the syringe into the user. For obtaining blood samples, the syringe is replaced by a striker element which actuates a spring loaded puncture module which punctures the skin and is quickly withdrawn.
U.S. Pat. No. 5,141,496 describes a syringe guide with adjustment of the depth to which the needle penetrates comprising a body having one end provided with a sliding base which is adjustable in position by means of a screw and whose other end includes a sliding part fixed to the syringe and loaded by a spring which on relaxing causes the needle to be plunged into the skin to a predetermined depth.
U.S. Pat. No. 5,250,026 shows an implant injector for animals adjustable for implant insertion depth. The distance that the injector needle or cannula extends past the nose of the injector is adjustable. The insertion depth adjustment is accomplished by moving the nose of the injector relative to the tip of the cannula that extends past the nose. In addition to adjusting the insertion depth, the cannula or needle may also be rotated to a plurality of positions relative to the injector handle. A spring loaded plunger, when released by a release button, will push the implant out the end of the cannula as the operator withdraws the cannula from the animal. The release button is designed as a safety trigger to avoid premature activation of the plunger during insertion of the needle. Needles or cannulas of various diameters and lengths may be interchanged in the injector. The spring loaded plunger for expelling the implant may be removed allowing the operator to replace the plunger with a different diameter and length plunger to match different size cannulas.
U.S. Pat. No. 5,104,380 teaches a syringe comprising a dose metering device provided by a cap rotatable with respect to a pen body to a position related to the dose of medicament to be injected. The rotation compresses a coil spring which is prevented from unwinding by cooperating ratchet teeth. When the dose is to be injected, a trigger slide is moved to the left causing the ratchet teeth to come out of engagement. This permits the spring to unwind thereby rotating a drive sleeve, drive gear and a drive plunger. The drive plunger is formed with a quick pitch screw thread so that its rotational movement is accompanied by axial movement to cause medicament to be discharged from a cartridge and injected through a needle.
U.S. Pat. No. 5,102,393 describes a autoinjector converted from an intramuscular to a subcutaneous mode of injection comprising a housing having a medicament cartridge assembly mounted within the housing means in a storage position for movement out of the storage position and a releasable stressed spring assembly for moving the medicament cartridge assembly means out of the storage position. The stressed spring assembly is operable in response to a manual actuating procedure which does not require compression of the subcutaneous tissue to effect an intramuscular mode of injection by moving the hypodermic needle of the cartridge assembly outwardly of the housing into the muscle tissue at the injection site of a user and a major portion of the liquid medicament of the cartridge assembly outwardly through the hypodermic needle into the muscle tissue of the user. An injection mode converting structure is secured in a subcutaneous mode position for converting the mode of injection effected by the stressed spring assembly from the intramuscular mode of injection to a subcutaneous mode of injection in which the needle cannot extend substantially beyond subcutaneous tissue at the injection site of the user and a major portion of the liquid medicament enters into the subcutaneous tissue.
U.S. Pat. No. 4,231,368 shows a pistol-like casing for mounting a tubular holder containing a syringe in the gun barrel portion of the casing so it may be cocked in the withdrawn position against the force of a spring and released by movement of an arresting pawl. Pulling back a trigger advances a push rod that first trips the pawl, then brings force to bear against the pistol rod of the syringe. After the needle is driven into the skin by the release of the pawl and the actuating mechanism has been brought to bear against the syringe piston-rod, the injection of the syringe contents can proceed under control of hand feel without any necessity of changing or shifting the hand grip by continuing to pull the trigger back.
U.S. Pat. No. 3,538,916 teaches an injection pistol for intramuscular implantation of encapsulated liquid or solid chemical material into animals. The depth of injection of the needle into the animal muscle is controlled by an injection depth gauge mounted on the injection needle. A shaft means having a slidable plunger means integral therewith is mounted on the frame and is utilized to eject the chemical material from within the injection needle and implant the chemical material into the animal muscle after the needle is thrust into the muscle. The travel of the plunger means within the injection needle is limited by a threadedly adjustable depth stop means mounted on the end of the shaft means opposite to the plunger means.
U.S. Pat. No. 4,270,537 describes a hypodermic syringe and automatic needle insertion device wherein the syringe is biased against a trigger when the needle is in the retracted position. Upon release of the trigger, the syringe and needle are driven forward extending the needle into the underlying tissue. The depth of insertion may be predetermined by the attachment of an interchangeable stop.
Additional examples of the prior art are found in U.S. Pat. No. 4,333,459; U.S. Pat. No. 5,092,376 and U.S. Pat. No. 5,183,465.